implementation module lex
-import Data.Either
-import Data.List
+import Control.Monad, Control.Applicative
+import Data.Either, Data.Func, Data.Maybe, Data.Functor
+from StdFunc import o
+import StdBool
+import StdList
+import StdChar
import StdString
-import System.CommandLine
-import StdFile
-import StdMisc
-// Misschien moeten we hier continuation style van maken
-instance toString lexerOutput where
- toString l = "dit is een lexer output, danwel error\n"
+from Text import class Text(textSize,concat), instance Text String
+
+import yard
lexer :: [Char] -> LexerOutput
-lexer _ = Left "Not Implemented"
-
-Start :: *World -> *World
-Start w
-# (args, w) = getCommandLine w // We lezen nu nog standaard van stdin
-# (out, w) = stdio w
-# (toparse, out) = readEntireFile out
-# out = out <<< toString (lexer toparse)
-# (b, w) = fclose out w
-| not b = setReturnCode 1 w
-= w
+lexer r = case runParser (lexProgram 1 1) r of
+ (Right p, _) = Right p
+ (Left e, _) = Left e
+
+lexProgram :: Int Int -> Parser Char [Token]
+lexProgram line column = lexToken >>= \t->case t of
+ LexEOF = pure []
+ (LexItemError e) = fail <?>
+ PositionalError line column ("LexerError: " +++ e)
+ (LexToken c t) = lexProgram line (column+c)
+ >>= \rest->pure [{line=line, column=column, token=t}:rest]
+ LexNL = lexProgram (line+1) 1
+ (LexSpace l c) = lexProgram (line+l) (column+c)
+
+:: LexItem
+ = LexToken Int TokenValue
+ | LexSpace Int Int
+ | LexNL
+ | LexEOF
+ | LexItemError String
+
+lexToken :: Parser Char LexItem
+lexToken =
+ //Comments
+ lexBlockComment <|> lexComment <|>
+ //Keyword tokens
+ lexKw "var" VarToken <|> lexKw "Void" VoidToken <|>
+ lexKw "return" ReturnToken <|> lexKw "if" IfToken <|>
+ lexKw "else" ElseToken <|> lexKw "while" WhileToken <|>
+ lexKw "True" TrueToken <|> lexKw "False" FalseToken <|>
+ lexKw "Int" IntTypeToken <|> lexKw "Bool" BoolTypeToken <|>
+ lexKw "Char" CharTypeToken <|>
+ //Character tokens
+ lexEscape <|> lexCharacter <|>
+ //Two char ops tokens
+ lexWord "::" DoubleColonToken <|> lexWord "!=" NotEqualToken <|>
+ lexWord "<=" LesserEqToken <|> lexWord ">=" GreaterEqToken <|>
+ lexWord "==" EqualsToken <|> lexWord "&&" AmpersandsToken <|>
+ lexWord "||" PipesToken <|> lexWord "[]" EmptyListToken <|>
+ lexWord "->" ArrowToken <|>
+ //One char ops tokens
+ lexWord "(" BraceOpenToken <|>
+ lexWord ")" BraceCloseToken <|> lexWord "{" CBraceOpenToken <|>
+ lexWord "}" CBraceCloseToken <|> lexWord "[" SquareOpenToken <|>
+ lexWord "]" SquareCloseToken <|> lexWord "," CommaToken <|>
+ lexWord ":" ColonToken <|> lexWord ";" SColonToken <|>
+ lexWord "." DotToken <|> lexWord "+" PlusToken <|>
+ lexWord "*" StarToken <|> lexWord "/" SlashToken <|>
+ lexWord "%" PercentToken <|> lexWord "=" AssignmentToken <|>
+ lexWord "<" LesserToken <|> lexWord ">" BiggerToken <|>
+ lexWord "!" ExclamationToken <|> lexWord "-" DashToken <|>
+ //Number and identifier tokens
+ lexNumber <|> lexIdentifier <|>
+ (item '\n' >>| pure LexNL) <|>
+ (satisfy isSpace >>| (pure $ LexSpace 0 1)) <|>
+ (eof >>| pure LexEOF)
where
- readEntireFile :: *File -> *([Char], *File)
- readEntireFile f
- # (b, c, f) = freadc f
- | not b = ([], f)
- # (cs, f) = readEntireFile f
- = ([c:cs], f)
+ lexWord :: String TokenValue -> Parser Char LexItem
+ lexWord s tv = list (fromString s) >>| pure (LexToken (textSize s) tv)
+
+ lexKw :: String TokenValue -> Parser Char LexItem
+ lexKw kw tv = lexWord kw tv <* check (not o isIdentChar)
+
+ lexUntilNL = top until (eof <|> (item '\n' >>| pure Void))
+
+ lexComment :: Parser Char LexItem
+ lexComment = list (fromString "//") >>| lexUntilNL
+ >>= \chars->pure LexNL
+
+ lexBlockComment :: Parser Char LexItem
+ lexBlockComment = list (fromString "/*")
+ >>| (top until (list (fromString "*/")))
+ >>= \chars->pure $ widthHeight chars 0 0
+ where
+ widthHeight :: [Char] Int Int -> LexItem
+ widthHeight [] l c = LexSpace l c
+ widthHeight ['\n':xs] l _ = widthHeight xs (l+1) 0
+ widthHeight [x:xs] l c = widthHeight xs l (c+1)
+
+ lexNumber :: Parser Char LexItem
+ lexNumber = toString <$> some (satisfy isDigit)
+ >>= \si->pure $ LexToken (textSize si) (NumberToken $ toInt si)
+
+ lexIdentifier :: Parser Char LexItem
+ lexIdentifier = toString <$> some (satisfy isIdentChar)
+ >>= \si->pure $ LexToken (textSize si) (IdentToken si)
+
+ isIdentChar c = isAlphanum c || c == '_'
+
+ lexCharacter :: Parser Char LexItem
+ lexCharacter = item '\'' *> satisfy ((<>) '\'') <* item '\''
+ >>= \char->pure $ LexToken 3 (CharToken char)
+
+ lexEscape :: Parser Char LexItem
+ lexEscape = item '\'' *> item '\\' *> top <* item '\''
+ >>= \char->pure case char of
+ 'a' = LexToken 4 (CharToken $ toChar 7)
+ 'b' = LexToken 4 (CharToken '\b')
+ 'b' = LexToken 4 (CharToken '\b')
+ 'f' = LexToken 4 (CharToken '\f')
+ 'n' = LexToken 4 (CharToken '\n')
+ 'r' = LexToken 4 (CharToken '\t')
+ 'v' = LexToken 4 (CharToken '\v')
+ '\'' =LexToken 4 (CharToken '\'')
+ c = (LexItemError $ "Unknown escape: " +++ toString c)
repositories / cc1516.git / blobdiff